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Represión de la absorción microbiana de arsenito y metilación por el carbono orgánico disuelto
Hyun Yoon1, Michael A P Vega1, Jiaxing Wang2
1School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, 14853, United States.
Environmental science & technology letters
|August 29, 2025
Resumen
La metilación microbiana del arsénico en los arrozales es reprimida por sustratos altos en carbono como la glucosa. Este mecanismo de represión de catabolitos de carbono (CCR) afecta la absorción de arsenito a través de los canales GlpF, lo que afecta la biogeoquímica del arsénico.
Área de la Ciencia:
- Microbiología ambiental
- Biogeoquímica
- Metabolismo del arsénico
Sus antecedentes:
- La metilación del arsénico es un proceso microbiano clave en el ciclo del arsénico, particularmente en los arrozales.
- La absorción microbiana de arsenita está mediada por la acuagliceroporina GlpF, vinculándola a la utilización de carbono orgánico.
Objetivo del estudio:
- Investigar la hipótesis de que los sustratos de carbono reprimen la absorción y la metilación de arseniito a través de la represión de catabolitos de carbono (CCR).
- Aclarar el papel de los canales GlpF y sustratos de carbono específicos en la regulación de la biotransformación del arsénico.
Principales métodos:
- Ensayos de biosensores de arsénico para medir la absorción de arsénico.
- RT-qPCR para analizar la expresión del gen *glpF*.
- Evaluación de la metilación de la arsenita por *Arsenicibacter rosenii* con diferentes sustratos de carbono.
Principales resultados:
- La absorción de arsenito fue reprimida por la glucosa y la materia orgánica disuelta.
- El aumento de las concentraciones de carbono condujo a la represión de la expresión génica *glpF*, reduciendo la absorción de arsenito.
- La metilación de la arsenita fue reprimida por sustratos glicolíticos superiores (glucosa, xilosa, manosa) pero no por piruvato o succinato.
Conclusiones:
- La disponibilidad de carbono orgánico, en particular los sustratos glicolíticos superiores, tiene un impacto significativo en la metilación microbiana del arsénico.
- La represión de catabolitos de carbono (CCR) es un mecanismo clave que regula la absorción y transformación de arsenito en entornos de arrozales.
- Los hallazgos ofrecen nuevos conocimientos sobre cómo el carbono orgánico afecta el ciclo microbiano del arsénico y la biotransformación.
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